The 5 in. hard black rubber wheels are non-marring, wear-resistant, and capable of rolling smoothly on concrete, grass, bare soil, and other indoor/outdoor surfaces.Equipped with a dual locking mechanism, these casters can simultaneously lock both the wheel rotation and swivel axle, eliminating safety hazards from accidental sliding during use-critical for elevated work platforms, equipment handling, and other stability-dependent scenarios. Pre-drilled holes simplify installation without professional tools, enhancing construction efficiency. With a 400 lbs. load capacity per wheel (1,600 lbs. total for the 4-pack), these casters are ideal for heavy-duty applications such as light machinery, equipment stands, flight cases, display equipment, cabinets, and furniture.The solid steel wheel shafts offer superior impact resistance compared to cast iron, while the non-marking rubber treads protect sensitive floors like tiles and hardwood. Built with a full-metal bracket and high-elastic rubber wheels, they withstand rigorous load testing and frequent use in harsh conditions, ensuring long-term durability. The 360° swivel axles with precision bearings enable smooth, low-resistance movement, allowing single-person operation of large equipment. The package includes 4 caster wheels, 4 installation pins, and matching screw accessories. Each wheel stands approximately 6 in. tall (including the wheel diameter) with a base plate compatible with most standard scaffold interfaces.